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no. 614,023. Patented Nov. 8, 1398. u. PERKINS. MANUFACTURE OF METALLIC TUBES.

(Application filed June 24, 1898.)

(No Model.) 2 Sheets-Sheet I.

f "j f No. s|4,023. Patented Nov. 8,1898. H. PERRINS.

MANUFACTURE OF METALLIC TUBES.

(A pplicatirm filed June 24, 1898.)

(No Model) 2 Sheets-Sheet 2.

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NITED STATES PATENT Germs.

HARRYPERRINS, F s'ME'rtiwIoK, ENGLAND;

MANUFACTURE OF METALLIC TUBES;

s'rncrrxonrrion forming part or Letters Patent No. 614,023, dated November 8, 1898. Application filed June 24,1898. Serial No. 684,412. (No model.)

To all whom it may concern:

Be it known that I, HARRY PERKINS, a subject of the Queen of Great Britain and Ireland,and a resident of 22 Grange road, Smethwick, in the county of Stafford, England, have invented certain new and useful Improvements in the Manufacture of Metallic Tubes, (for which I have filed an application for patent in Great Britain, No. 22,947, bearing date October 6, 1897,) of which the following is a specification.

This invention has reference to the manufacture of wrought steel and wrought-iron tubes for all purposes, and particularly for gas, steam, and water, and cold-drawn seamless steel tubes for cycle construction and other constructional purposes.

By my invention I am enabled to form at one heat afinished wrought iron or steel tube from rolled puddled bars or from other rolled iron bars or rolled steel bars of particular sections, as hereinafter described, thereby effecting a considerable saving in the cost of manufacture as compared with other processes, where the tube under operation has to be heated one or more times before being finished.

When applying my invention 'to the manufacture of cold-drawn tubes, I form and roll the tube down to a certain diameter and thickness in accordance with my invention and then reduce and finish the tube by cold-drawing in the usual way.

In the two accompanying sheets of explanatory drawings, to be hereinafter referred to,

Figure 1 is a cross-section of a piled hollow bloom formed of four rolled iron or steel bars, in accordance with my invention, for rolling down into a circular-section tube such as shown by Fig. 2. Fig. 3 is a side elevation, and Fig. 4 an end elevation, of one of the two inside bars of the said piled hollow bloom.,

Fig. 5 is a side elevation, and Fig. 6 an end elevation, of one of the two outside bars of the said piled'hollow bloom. Fig. 7 is a sectional elevation, and Fig. 8 a plan, of pairs of rolls arranged in a series and a bulbed mandrel which I employ in carrying out my invention. Fig. 9 shows, on a large scale, the piliid hollow bloom entering the first pair of r0 s.

The same letters of reference indicate the same parts in all the figures.

In making round-section wrought iron or steel tubes in accordance with my invention I first form what I call a piled hollow or tubular bloom as follows: In an ordinary rolling-mill with the rolls turned to the proper shapes I rollpuddled-iron bars or other iron or mild-steel bars of the two trough-section shapes represented in Figs. 1, 3, 4, 5, and 6. Two of these bars (marked A A are both of the same section and form the outside of the pile. The section of each of these bars A A somewhat resembles half a hexagonal cylinder, the division being longitudinal through two opposite angles. The side a, or bottom of the trough is flat to form a base for the pile to stand on, and the other two sides a a are somewhat rounded, approximating the shape of the required round tube. Care must be taken that the bars A and A when Fig. 1 has been built up, are so proportioned as to have a small space between them at the lines of j uncture a a. When the two bars A A are laid with their hollow sides adjacent, as shown in Fig. 1, they together have a tubular form. The other two bars B B which form the inside of the pile, are both of the same cross section, resembling half a cylinder which has, a circular or approximately circular bore and" on the outside is of approximately hexagonal form, the division being longitudinal across two opposite sides, the bars being of theproper size and shape so that when laid with their hollow sides together they will fit between the two bars A A as shown in Fig. 1. In building up the pile one of the outside bars-say A-is placed on its base a, and the two inner bars B B are then placed within the trough of the same with their meeting edges vertical, as shown in Fig. 1. The other bar A is'thenplaced on the top, so as to inclose the two bars 13 B and thus the four bars form, as shown by Fig. 1, what I calla piled hollow bloom made in four segments. It

will be seen that the longitudinal joints formed by the meeting of the two outer bars A A are lapped by the two inner bars B B and the longitudinal joints formed by the meeting of the two inner bars B B are lapped by the two outer bars A A No core or other filling material is required in forming this pile, nor do the bars require to be bound or otherwise fixed together, as the peculiar shapes of the bars prevent them from changing their positions relatively to one another unless the pile is upset, as it will be seen that the two inner bars B 13 cannot turn inside the two outer bars, nor can the latter get askew with each other. This piled hollow bloom is now raised to a welding temperature in a suitable furnace, being placed with one of its flat sides a on the furnace base or bed. By the pile having two fiat sides a a, forming the top and bottom of the pile, respectively, it can be turned over in the furnace and will stand steady on either of the flat sides and be edectually prevented from rolling about in the furnace. Vhen at a welding temperature, the pressure of the uppermost outer bar, as A Fig. 1, upon the inner bars 13 B and the pressure of the said bars B 13 upon the lower outer bar A (all caused by the fact that the spaces a a, permit the weight of the bar A to press upon B and B and all three A B B to press upon the inner surface of A) causes the parts to become united or partially welded along their adjoining circumferential surfaces, and by such Welding before removal from the furnace the parts will be secured and retained in their proper relative positions during the subsequent rolling operation, which completes the welding. \Vhen the said piled hollow bloom is being heated in the welding-furnace, it is found that the peculiar shapes of the bars, as illustrated, assist the adhering of the inside bars to the outside bars, because as the former become hot they expand somewhat after the welding or uniting of the circumferential surfaces has occurred, thereby pressing their rounded sides more closely against the inner surfaces of the two outer bars.

The rolling operation is accomplished by means of rolls and a stationary bulbed mandrel, by preference arranged as represented by Figs. '7 and 8.

I prefer to employ six pairs of grooved rolls, (more or less, according to the required reduction in area of the tube,) marked, respectively, O C C C (L 0 arranged in line with their axes horizontal, as in an ordinary rolling mill, and provided with semicircular grooves c, forming circular passes of gradu ally-diminishing area from the first pair of rolls 0 to the last pair C. The stationary bulbed mandrel D, which at its front end d engages with a fixed stationary cross-bar E, is carried through the passes of all the rolls and provided with plugs or swells, (markedfi) one for each pair of rolls, arranged in the pass to support the interior of the tube as it is being rolled. The said heated piled hollow bloom is threaded onto the mandrel D at its front end (1 (the mandrel D having previously been lifted out of the cross-bar E) and then is rolled through the first pair of rolls 0 and through each of the other pairs in order and is gradually reduced in diameter and lengthened until when the tube has passed through the last pair of rolls 0 it will be of the required finished size.

The various pairs of rolls are placed so far apart that the tube will not enter one pair until it has passed out of the preceding pair, so as to allow of the tube being turned a quarter around on the mandrel before the tube enters the next pair of rolls. This is necessary in order to roll down any rib or fin which may be formed on the tube at the junction of the rolls.

The piled hollow bloom enters the first pair of rolls C with the junction formed by the meeting faces of the outer bars A A vertical, as represented by Fig. 9, the object of this being that the surfaces of the two rolls pressing on the pile in the directions indicated by the arrows in Fig. 9 will very effectually press the two outer bars A A together and against the two inner bars B B thereby at once perfectly welding the four bars together. Thus the piled hollow bloom is rolled down at one heat thin enough to form some kinds of wrought iron and steel tubes such, for instance, as gas, steam, and water tubesbut when a further reduction of thickness and diameter and increased elongation are required this is done in the case of the steel tubes by cold-drawing on a draw-bench or by other well-known means.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In the manufacture of metallic tubes, the combination of rolled trough-section bars disposed within and without each other forming a piled hollow bloom with spaces between the adjacent longitudinal edges of the upper and lower outer bars, the weight of the upper outer bar being supported by the contact of its inner circumferential surface with the outer circumferential surface of the inner bars and with the combined weight of the upper outer bar and the inner bars supported by the contact of the said inner bars with the inner circumferential surface of the lower outer bar resting on the bed of the furnace, substantially as described.

2. A piled hollow bloom composed of outer sections A A having flatupper and lower surfaces and internallycurved sides, said sections being separated horizontally from each otherand inner sections correspondingly shaped and separated vertically from each other, substantially as described.

In witness whereof I have hereunto set my hand in presence of two witnesses.

HARRY PERRINS.

Witnesses:

EDWARD MARKs, HERBERT BoWKErT. 

